The present invention relates to a curtain air bag apparatus for protecting an occupant by inflating and deploying an air bag body into a curtain-like shape in a side surface of a vehicle interior with a high pressure gas instantaneously provided and introduced into the air bag body by an inflator upon a vehicle collision.
In recent years, there have been proposed and developed various curtain air bag apparatuses. One such curtain air bag apparatus has been disclosed in Japanese Patent Provisional Publication No. 2004-034766 (hereinafter is referred to as “JP2004-034766”). In JP2004-034766, an occurrence of a rebound phenomenon is avoided by reducing an peak acceleration which the occupant suffers by an air bag body inflated and deployed into a curtain-like shape along a side surface of a vehicle interior, and also the inflated air bag body is prevented from excessively deflating, then a sufficient time for restraining an occupant can be secured.
The air bag apparatus in JP2004-034766 has, as shown in FIG. 9, a front protection area “b”, a rear protection area “c”, of an air bag body “a”, and a sub-inflation part “d” formed between the front and rear protection areas “b and c”. Further, a vent hole “e” through which the front protection area “b” and the sub-inflation part “d” communicate, is provided. With this structure, when internal pressures of the front and rear protection areas “b and c” increase due to a load by the inflated air bag body restraining the occupants seated in both front and rear seats in the vehicle interior, a part of high pressure gas in the both protection areas “b and c” flows into the sub-inflation part “d” through the vent hole “e”. The internal pressure of the front and rear protection areas “b and c” can be then lowered, and the peak acceleration exerted on the occupant can be reduced. Thus the occurrence of the rebound phenomenon can be avoided and the inflated protection areas “b and c” can be prevented from excessively deflating, and the sufficient time for restraining the occupant can be secured.